Drain Protection

ABSTRACT

A protected drain assembly comprising a drain which is at least partially bordered by a hard surface, and which is protected by a drain cover assembly which comprises
         (A) a polymeric sheet which is on top of the drain and (a) comprises a central portion which, when a sediment-containing liquid is placed on top of it, allows liquid to pass through it, or (b) is substantially impervious to water; and   (B) gaskets which are attached to edges of the polymeric sheet and secure the edges of the polymeric sheet to the hard surface.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PATENTS

This application is a continuation of, and claims priority from,copending application Ser. No. 16/005,347 filed Jun. 11,2018 by ErtecEnvironmental Systems LLC. Application Ser. No. 16/005,347 is acontinuation-in-part of, and claims priority from, application Ser. No.15/285,430 filed Oct. 4, 2016, by Ertec Environmental Systems LLC. Thisapplication also claims priority from application Ser. No. 15/285,430,filed Oct. 4, 2016. This application is also related to U.S. Pat. Nos.6,848,866, 7,008,144 7,131,787, 7,172,372, 7,554,016, 7,955,030 and8,402,630 and to U.S. patent application Ser. No. 14/279,977, filed May16, 2014. The entire disclosure of each of those patents and thoseapplications is incorporated by reference herein for all purposes.

BACKGROUND OF THE INVENTION

This invention relates to assemblies and methods for protecting drains.

SUMMARY OF THE INVENTION

In a first aspect, this invention provides a drain cover assembly whichcan be placed over a drain in the road and which comprises

-   -   (A) a self-supporting polymeric sheet which comprises        -   (1) a central portion,        -   (2) a first side edge portion which contacts and extends            from one side of the central portion,        -   (3) a second edge portion which contacts and extends from an            opposite side of the central portion,        -   (4) a front edge portion which (i) contacts and extends from            a front edge of the central portion and (ii) is attached to            the first and second edge portions, and        -   (5) a rear edge portion which (i) contacts and extends from            a rear edge of the central portion and (ii) is attached to            the first and second edge portions;    -   (B) a first side edge gasket which (i) comprises an inner gasket        portion which contacts and lies over or under the first side        edge portion of the polymeric sheet and (ii) an outer gasket        portion which extends away from the first side edge portion of        the polymeric sheet; and    -   (C) a second side edge gasket which (i) comprises an inner        gasket portion which contacts and lies over or under the second        side edge portion of the polymeric sheet and (ii) an outer        gasket portion which extends away from the second side edge        portion of the polymeric sheet.        The term polymeric sheet is used in this specification        (including the claims) to denote a sheet which is composed of an        organic polymer and, optionally, conventional additives such as        fillers.

The preferred size of the polymeric sheet is determined by the size ofthe drain to be protected, and, when relevant, the largest size that canbe conveniently shipped. The polymeric sheet will normally cover theentire drain, but it may extend beyond the drain on one or more sides.For rectangular (including square) drains, the length of each side willoften be 2-6 feet, e.g. 2-4 feet. For long thin drains (e.g. slot drainsand trench drains), the polymeric sheet may for example be 4-9 incheswide and up to 7 feet long. When necessary or convenient, two or moredrain cover assemblies can be used together for very large drains.

In some embodiments of the invention, at least part of the centralportion of the polymeric sheet comprises apertures which allow water topass through the central portion into a drain over which the assemblyhas been placed. In other embodiments, the polymeric sheet and each ofthe edge gaskets allows little or no water to pass through it, so thatlittle or no water can enter a drain over which the assembly has beenplaced.

In a first embodiment of the first aspect of the invention, the draincover assembly is particularly useful for protecting a drain which islong and thin and which optionally comprises members which, when thedrain cover is in place, support part of the central portion of thepolymeric sheet. In this embodiment, (i) the drain cover includes thefirst side edge gasket and the second side edge gasket, (ii) each of thegaskets extends beyond the end of the polymeric sheet, and (iii) thecentral portion of the polymeric sheet extends beyond the ends of thedrain; and (iv) the presence of edge gaskets at the ends of thepolymeric sheet is optional.

In a second embodiment of the first aspect of the invention, the draincover assembly (i) is particularly useful for protecting a drain which(a) is rectangular, with substantial width and length, (b) comprisesmembers which, when the drain cover is in place, support at least partof the polymeric sheet and (c) is bordered on all sides by a roadway,parking lot, service yard, floor of a waste management transfer stationor industrial production facility, or other hard surface. For this use,the drain cover assembly comprises, in addition to the first and secondside edge gaskets,

-   -   (D) a front edge gasket which (i) comprises an inner gasket        portion which contacts and lies over or under the front edge        portion of the polymeric sheet, (ii) comprises an outer gasket        portion which extends away from the front edge portion of the        polymeric sheet and (iii) contacts the first side edge gasket        and the second side edge gasket;    -   (E) a rear edge gasket which (i) comprises an inner gasket        portion which contacts and lies over or under the rear edge        portion of the polymeric sheet, (ii) comprises an outer gasket        portion which extends away from the front edge portion of the        polymeric sheet and (iii) contacts the first side edge gasket        and the second side edge gasket.

In a third embodiment of the first aspect of the invention, the draincover assembly is particularly useful for protecting a drain which (a)is rectangular, with substantial width and length, (b) comprises memberswhich, when the drain cover is in place, support at least part of thecentral portion of the polymeric sheet, (c) is bordered by a roadway orother hard surface on the front and on each side, and (d) has a rearsection which is an opening in a curb of a sidewalk. For this use, thedrain cover assembly comprises, in addition to the first and second sideedge gaskets,

-   -   (D) a front edge gasket which (i) comprises an inner gasket        portion which contacts and lies over or under the front edge        portion of the polymeric sheet, (ii) comprises an outer gasket        portion which extends away from the front edge portion of the        polymeric sheet and (iii) contacts the first side edge gasket        and the second side edge gasket.        In this use, the polymeric sheet optionally has a rear edge        portion which is not covered by the side edge gaskets and which,        when the drain assembly is in use, extends upwards from the        central portion of the polymeric sheet to cover at least part of        the opening in the curb of the sidewalk. The rear edge portion,        when it extends upwards from the central portion of the        polymeric sheet, can be created by bending upwards the rear edge        portion of the polymeric sheet before or after the gaskets are        secured to the central portion of the polymeric sheet and before        or after the drain cover has been placed over the drain.

In a second aspect, this invention provides a protected drain assemblywhich comprises

-   -   (1) a drain which is bordered on at least three sides by a hard        surface, and    -   (2) a drain cover assembly according to the first aspect of the        invention,        wherein (a) at least part of the central portion of the        polymeric sheet lies over the drain, (b) the drain optionally        comprises members which contact and support at least part of the        central portion of the polymeric sheet, (c) at least part of the        inner gasket portion of the first side edge gasket is over the        drain or over a part of the hard surface which borders the        drain, (d) at least part of the outer gasket portion of the        first side edge gasket contacts a part of the hard surface which        borders the drain, (e) at least part of the inner gasket portion        of the second side edge gasket is over the drain or over a part        of the hard surface which borders the drain, and (f) at least        part of the outer gasket portion of the second side edge gasket        is over the drain or over the hard surface which borders the        drain.

In a third aspect this invention provides a method of preparing aprotected drain assembly comprising a drain which is at least partiallybordered by a hard surface, the method comprising

-   -   (A) placing over the drain a polymeric sheet which comprises        -   (1) a central portion,        -   (2) a first side edge portion which contacts and extends            from one side of the central portion,        -   (3) a second edge portion which contacts and extends from an            opposite side of the central portion,        -   (4) a front edge portion which (i) contacts and extends from            a front edge of the central portion and (ii) is attached to            the first and second edge portions,        -   (5) a rear edge portion which (i) contacts and extends from            a rear edge of the central portion and (ii) is attached to            the first and second edge portions;    -   and    -   (B) before or after step (A), providing gaskets which (i) are        attached to at least two edges of the polymeric sheet and (ii)        secure the edges of the polymeric sheet to the hard surface.

In a fourth aspect, this invention provides a gasket which is suitablefor use in the drain cover assemblies of the first aspect of theinvention and which is a strip of a porous nonwoven fabric, preferably amelt blown polymeric fabric, which has been folded lengthwise so that itcomprises

-   -   (A) an inner gasket portion,    -   (B) an outer gasket portion which is coplanar with the inner        gasket portion, and    -   (C) a berm which extends upwards from the inner and outer gasket        portions.        The gasket is preferably formed by (1) folding the strip of the        fabric lengthways, (2) sewing a lengthways seam between the two        sides of the fabric, with the distance of the seam from the tip        of the fold determining the height of the berm, and (3)        flattening the strip of fabric.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in the accompanying drawings which arediagrammatic sketches and are not to scale, and in which

FIG. 1 is a partial cross-section of a polymeric sheet for use in someembodiments of the invention,

FIG. 2 is a partial cross-section of an edge gasket for use in theinvention,

FIGS. 3-7 are partial cross-sections of different covered drainassemblies of the invention, and

FIGS. 8-11 are plan views of different drain cover assemblies of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

In the Summary of the Invention above, the Detailed Description of theInvention, the Examples, and the claims below, and in the accompanyingdrawings, reference is made to particular features of the invention,including for example components, ingredients, devices, apparatus,systems, test results and steps. It is to be understood that thedisclosure of the invention in this specification includes all possiblecombinations of such particular features. For example, where aparticular feature is disclosed in the context of a particular mode,aspect, embodiment, Figure or claim, that feature can also be used, tothe extent possible, in the context of any other particular mode,aspect, embodiment, Figure or claim, and in the invention generally. Theinvention disclosed and claimed herein includes embodiments notspecifically described herein and can for example make use of featureswhich are not specifically described herein but which provide functionswhich are the same, equivalent or similar to, features specificallydisclosed herein.

The term “comprises” and grammatical equivalents thereof are used hereinto mean that other features are optionally present. For example, thedrain cover assembly defined above which comprises the specifiedcomponents (A), (B) and (C) can consist of those specified components orcan also contain other components, for example the specified components(D) and (E), or other non-specified components. Where reference is madeherein to a method comprising two or more defined steps, then, unlessthe context requires otherwise, the defined steps can be carried out inany order or simultaneously, and the method can include one or moreother steps which are carried out before any of the defined steps,between two of the defined steps, or after all the defined steps. Theterm “at least” followed by a number is used herein to denote the startof a range beginning with that number (which may be a range having anupper limit or no upper limit, depending on the variable being defined).For example “at least 1” means 1 or more than 1, and “at least 80%”means 80% or more than 80%. When, in this specification, a range isgiven as “ (a first number) to (a second number)” or “(a firstnumber)−(a second number)”, this means a range whose lower limit is thefirst number and whose upper limit is the second number. For example,“0.5-3” means a range whose lower limit is 0.5, and whose upper limit is3. The numbers given herein should be construed with the latitudeappropriate to their context and expression. The terms “plural” and“plurality” are used herein to mean two or more. When reference is madeherein to “a”, “an”, “one” or “the” feature, it is to be understoodthat, unless the context requires otherwise, there can be one or morethan one such feature.

Where reference is made herein to two or more components (or parts orportions etc.), it is to be understood that the components can be,unless the context requires otherwise, separate from each other orintegral parts of a single structure or a single component acting as thetwo or more specified components.

When reference is made herein to a component being on one side, or atthe front, or at the rear, or upwards or downwards, of an assembly, thereference is to the assembly in the horizontal position.

The Polymeric Sheets. Polymeric Sheets Through Which Water Can Pass.

As previously noted, in some embodiments of the invention, at leastpart, and preferably all, of the central portion of the polymeric sheetcomprises one or more apertured sheet materials in which the aperturesallow liquid to pass through the sheet. In some embodiments, thepolymeric sheet comprises, and optionally consists of, (1) a singleapertured polymeric sheet, or (2) two or more apertured polymeric sheetswhich are joined together. The size of the apertures in the aperturedpolymeric sheet or sheets is preferably such that, when the assembly isplaced over a drain, solids entrained in the liquid, e.g. debris,leaves, twigs and other materials having a similar or greater size, donot pass through the polymeric sheet into the drain.

The apertured polymeric sheet, or at least one of the aperturedpolymeric sheets if there are two or more polymeric sheets joinedtogether can for example have one or more of the following optionalcharacteristics.

-   -   (1) In the polymeric sheet, and in at least one of the polymeric        sheets if there is more than one polymeric sheet, the apertures        have the same size and/or shape.    -   (2) In the polymeric sheet, and in at least one of the polymeric        sheets if there is more than one polymeric sheet, each of the        apertures has an area of 0.01 to 1.0 in.², preferably 0.02 to        0.25 in.², and/or a minimum dimension of 0.1 to 1.0, preferably        0.15 to 0.5, inch.    -   (3) The polymeric sheet, and at least one of the polymeric        sheets if there is more than one polymeric sheet, is composed        of (a) a first set of polymeric strands (i) which are parallel        to each other and (ii) are spaced apart from each other with a        distance between adjacent strands of 0.1-1.0, e.g. 0.1 to 0.3        inch, and (b) a second set of polymeric strands (i) which are        parallel to each other and at an angle of 30 to 90° to the first        strands, (ii) which are bonded to the first strands of crossover        points, and (iii) which are spaced apart from each other with a        distance between adjacent strands of 0.1-1.0, e.g. 0.1 to 0.3        inch. The first and second polymeric strands can have a        thickness in the laminar dimension of the sheet direction of the        sheet between the crossover points of 0.04 to 0.5 inch.    -   (4) The polymeric sheet, and each of the polymeric sheets if        there is more than one polymeric sheet, is composed of a        polymeric composition which does not absorb substantial amounts        of water and which can be recycled, for example a composition        based on a polyolefin, particularly high density polyethylene or        polypropylene.    -   (5) The polymeric sheet, and at least one of the polymeric        sheets if there is more than one polymeric sheet, has a tensile        strength in the machine direction of at least 400 pounds (ASTM        D 4595) and in the transverse direction of at least 325 pounds        (ASTM D4595).    -   (6) The solid surface area of the polymeric sheet is 10 to 80%,        for example 25 to 65%, of its total area, both areas being        viewed at right angles to the sheet material        Additional details of suitable sheet materials are disclosed in        U.S. Pat. Nos. 6,848,868, 8,402,630 and the other US patents        which are incorporated herein by reference.

In some embodiments, at least part of the central portion of theapertured polymeric sheet comprises one or more first aperturedpolymeric sheets having relatively large apertures and a second sheetmaterial through which water can pass but whose resistance to thepassage of solids entrained in the water is greater than the first sheetor sheets. The second sheet material can, for example, be a secondapertured polymeric sheet in which the apertures have a size less thanthe apertures in the first polymeric sheet or sheets. The second sheetmaterial can act as a filter material so that, when asediment-containing liquid is placed on top of the sheet, the liquid canpass through it but at least some of the sediment (although it can passthrough the first polymeric sheet or sheets) is retained by the filtermaterial. The additional sheet material can also be engineered so thatit reduces the amount of other organic matter and chemicals, includinghydrocarbons and aluminum, entering the drain.

When the self-supporting polymeric sheet includes one or more aperturedfirst polymeric sheets and a second sheet material which acts as afilter, it is possible that in some circumstances, the area of thepolymeric sheet which includes the second sheet material will becomeclogged by sediment and debris so that the drain ceases to functionefficiently. To avoid this happening, it is possible for at least partof the polymeric sheet to be free of filter material, so that water canpass freely into the drain through that part of the polymeric sheet.

In one embodiment, the polymeric sheet comprises (i) two first polymericsheets having relatively large apertures therethrough, and (ii)sandwiched between the two first and second sheet materials, anadditional sheet material having relatively small aperturestherethrough. The additional sheet material can extend over part or allof the area of the polymeric sheet.

The second sheet material, which has relatively small apertures thereinand which, in use, acts as a filter for sediment, can for example haveone or more of the following optional characteristics.

-   -   (1) It has a mesh size (measured by ASTM E-11) of 80 to 600 μm,        preferably 100 to 500 μm,    -   (2) It has a substantially uniform thickness of less than 0.5        inch, or less than 0.25 inch, for example 0.01-0.06, preferably        0.01-0.04 inch.    -   (3) It is composed of a polymeric composition which does not        absorb substantial amounts of water, and which can be recycled        in the same batch as the first and second sheet materials, for        example a composition based on a polyolefin, particularly high        density polyethylene or polypropylene.    -   (4) In tests in which clean water is passed through the second        sheet material, on its own, the second sheet material is capable        of passing at least 100, e.g. at least 200, gallons of water per        square foot per minute, but not more than 600, e.g. not more        than 400, gallons of water per square foot per minute.        Additional details of suitable sheet filter materials are        disclosed in U.S. Pat. No. 6,848,868 and the other US patents        which are incorporated herein by reference.

When the polymeric sheet includes two or more apertured polymeric sheetshaving the same or different apertures therein, the sheets can besecured to each other in any convenient way, for example by intermittentspot welding, sewing or stapling.

The polymeric sheet comprises a central portion, a first side edgeportion, a second side edge portion, a front edge portion and a rearedge portion. These different portions will often be part of the samepolymeric sheet, with or without an additional sheet of filter material,so that the edge portions have the same construction as the centralportion.

In one embodiment, the central portion of the polymeric sheet is in theform of a broad peripheral border which (i) surrounds an opening which(a) is not covered by the polymeric sheet and when the drain coverassembly is in use, is open to the drain, and (ii) is surrounded by aninternal gasket. This embodiment is useful when large water flows areexpected, because the opening in the self-supporting polymeric sheetenables water to enter directly into the drain. The area of the openingcan be for example 0.1-0.3 times the area of the peripheral bordersurrounding the opening.

Polymeric Sheets Which Are Substantially Impervious to Water.

In some embodiments of the invention, the polymeric sheet allows littleor no water to pass through it. The polymeric sheet can be a singlesheet of polymeric material or two or more sheets of the same ordifferent polymeric materials. The sheet or sheets are preferablycomposed of a polymeric composition (i.e. a composition which contains apolymer and conventional additives such as fillers) which does notabsorb substantial amounts of water, and which can be recycled in thesame batch as the edge gaskets, for example a composition based on apolyolefin, particularly high density polyethylene or polypropylene.

The polymeric sheet, and at least one of the polymeric sheets if thereis more than one polymeric sheet, preferably has a tensile strength inthe machine direction of at least 400 pounds (ASTM D 4595) and in thetransverse direction of at least 325 pounds (ASTM D4595).

The Edge Gaskets.

In most cases, each of the edge gaskets, in use, bridges the junctionbetween an edge of the drain and a hard surface bordering the drain.However, it is also possible for the whole of the edge gasket to be overthe adjacent hard surface. As noted above, the drain cover assembly mayhave two, three or four edge gaskets, depending upon the type of drainwhich is to be protected. Each gasket has an inner gasket portion and anouter gasket portion.

The inner gasket portion contacts and lies over or under an edge portionof the polymeric sheet and preferably is secured to the top or thebottom of the polymeric sheet, for example by sewing. In use, preferably(i) all the inner gasket portion lies over the drain itself or (ii) partof the inner gasket portion lies over the drain and part lies over thehard surface which borders the drain. However, it is also possible forthe entire inner gasket portion to lie over the hard surface whichborders the drain. The inner gasket portion can for example be 0.5-5.0inches, for example 2-5 inches, preferably 3-4 inches, wide.

The outer gasket portion extends away from the inner gasket portion andaway from the edge of the polymeric sheet. In use, at least part of theouter gasket portion contacts the hard surface which borders the drain.The outer gasket portion can for example be 3-10 inches, preferably 5-7inches, wide.

The gaskets are preferably composed of a porous nonwoven fabric, forexample a melt blown nonwoven fabric, particularly a melt blownpolypropylene nonwoven fabric. The fabric can for example have athickness of 0.01-0.5 inch, preferably 0.1-0.4 inch, e.g. 0.2-0.3 inch.Suitable materials for the gasket are commercially available asgeotextile fabrics having a weight of 10-16 ounces per square yard. Wehave found that the use of a porous nonwoven fabric is advantageousbecause the outer portion of the gasket, at least part of which contactsthe hard surface adjacent the drain, adapts to and clings closely tomost hard surfaces, particularly when the gasket is wet. However, thebond between the gasket and the hard surface adjacent the drain can beeasily ruptured by pulling the gasket away from the hard surface.

Other materials can be used for the gaskets, for example in gaskets inwhich the underside of the outer gasket portion is coated with amaterial that adheres to the hard surface adjacent the drain. The gasketis preferably composed of a single strip of a single fabric, but cancomprise two or more different fabrics or materials.

The total horizontal width of the gasket can for example be 4-15 inches,preferably 6-12 inches. The widths of the inner and outer gasketportions can be the same or different.

In the assemblies in which there are three or four gaskets attached toedge portions of the polymeric sheet, the gaskets are preferably joinedtogether at the corners of the polymeric sheet, preferably by sewingand/or staples, optionally using auxiliary pieces of the same ordifferent fabric to secure the corner together.

In the assemblies in which there are only two gaskets attached toopposite edge portions of the polymeric sheet, each end of each gasketpreferably extends beyond the polymeric sheet.

Berms on the Gaskets.

In many cases it is preferred that at least one of the gaskets, andoptionally each of the gaskets, comprises an upstanding berm. The bermpreferably (i) is between the inner gasket portion and the outer gasketportion and (ii) extends upwards away from the inner gasket portion andthe outer gasket portion. In use, the berm is parallel to an edge of thepolymeric sheet and when a strong flow of liquid approaches the drain,the berm diverts the liquid flow. When the central portion of thepolymeric sheet comprises apertures which allow water to pass throughthe central portion, the presence of one or more berms reduces theamount of entrained solids in the liquid passing into the drain, thusincreasing the likelihood that the drain will function efficiently. Whenthe polymeric sheet is substantially impervious to water, the one ormore berms can divert the flow of water to another location (which maybe another drain).

The height of the berm can for example be 0.01-5.0 inch, preferably 1-3inch, e.g. about 1.5 inch. The height of the berm is preferably selectedwith a view to the expected water flows approaching the drain. When thesurface surrounding the drain is flat, it can be best to have only avery shallow berm or no berm at all, to avoid flooding the surfacesurrounding the drain when there is heavy rainfall.

When the gasket is composed of a fabric, preferably a nonwoven fabric,the berm can conveniently be made by folding a strip of the fabriclengthways and sewing a lengthways seam between the two sides of thefabric, with the distance of the seam from the tip of the fold beingapproximately the desired height of the berm. The fabric can then beflattened so that the inner and outer gasket portions are horizontal anda berm of the desired height extends upwards from them. The gasket canthen be secured to the polymeric sheet.

Internal Gaskets.

In one embodiment of the invention, the central portion of the polymericsheet is in the form of a broad peripheral border which (i) surrounds anopening which (a) is not covered by the polymeric sheet and, when thedrain cover assembly is in use, is open to the drain, and (ii) issurrounded by a plurality of gaskets which are joined together to forman internal gasket surrounding the opening. Each of the internal gasketssurrounding the opening can be generally the same as the edge gasketsdescribed above, with the inner gasket portion secured to the polymericsheet; the outer gasket portion may or may not be present.

THE DRAWINGS

In the drawings, the following numerals are used to denote differentcomponents of the assemblies.

-   -   1 denotes a polymeric sheet which is composed of first and        second sheet materials 11 and 12 and, sandwiched between the        sheet materials 11 and 12, an additional sheet material 13.    -   2 denotes a gasket which comprises an inner gasket portion 21,        an outer gasket portion 22, and an upstanding berm 23 formed by        folding a strip of a porous nonwoven fabric and securing the        fold by means of stitches 231.    -   3 denotes a drain.    -   4 denotes a hard surface bordering the drain.    -   15 denotes a rear edge portion of the polymeric sheet which        extends upwards from the central portion of the polymeric sheet        and can cover at least part of an opening in a curb of a        sidewalk 5.    -   6 denotes an internal gasket which (i) comprises an inner gasket        portion 62 and an upstanding berm 63, and (ii) surrounds an        opening 7 in the self-supporting polymeric sheet, the opening        being defined by a peripheral border portion 8 of the        self-supporting sheet.

Referring now to FIG. 1, each of the first and second sheet materials 11and 12 is an apertured polymeric sheet material having relatively largeapertures therethrough, and the additional sheet material 13 is a sheetmaterial having relatively small apertures therethrough, for example aconventional filter material which retains at least some of the sedimentcontained in a sediment-containing liquid placed on top of the draincover. As noted above, in some embodiments of the invention, part or allof the polymeric sheet comprises three sheet materials as shown inFIG. 1. In other embodiments of the invention, the polymeric sheetconsists essentially of a single apertured polymeric sheet or two ormore apertured polymeric sheets having apertures which allow sediment topass through the polymeric sheet into the drain.

Referring now to FIG. 2, the gasket is formed from a strip of a porousnonwoven fabric which has first been folded lengthways at anintermediate point, optionally at a midpoint of the strip, has then beensewn along the length of the fold, and finally has been flattened intothe shape shown in FIG. 2.

Referring now to FIG. 3, this shows a gasket 2 bridging the gap betweena drain 3 and a hard surface 4 bordering the drain. The inner gasketportion 21 is secured underneath the polymeric sheet 1 and rests on thedrain, and the outer gasket portion 22 rests on the hard surface 4.

Referring now to FIG. 4, this is the same as FIG. 3 except that theinner gasket portion is secured on top of the polymeric sheet 1.

Referring now to FIG. 5, this is the same as FIG. 3, except that thegasket 2 does not have an upstanding berm.

Referring now to FIG. 6, this is the same as FIG. 4, except that thegasket 2 does not have an upstanding berm.

Referring now to FIG. 7, this shows a front gasket 2 bridging the gapbetween a drain 3 and a hard surface 4 bordering the drain, with theinner gasket portion 21 secured over the polymeric sheet 1 which restson the drain, and with the outer gasket portion 22 resting on the hardsurface 4. A rear portion 15 of the polymeric sheet extends upwards fromthe horizontal portion of the polymeric sheet and covers an opening inthe curb of a sidewalk 5. The rear portion of the polymeric sheet can besecured in place by sandbags (not shown) at each end of the opening.

Referring now to FIG. 8, this shows a drain cover assembly which issuitable for the protection of a long thin drain. A gasket 2 is attachedto each side of a long thin polymeric sheet 1, with the inner gasketportion 21 secured to the top of the polymeric sheet 1. In use, thepolymeric sheet 1 extends beyond the drain.

Referring now to FIG. 9, this shows a drain cover assembly which issuitable for the protection of a drain which is bordered on all sides bya hard surface. The assembly comprises four gaskets, one on each edge ofthe polymeric sheet 1, each gasket having an upstanding berm 23, aninner gasket portion 21 secured underneath the polymeric sheet 1 and anouter gasket portion 22 extending beyond the berm.

Referring now to FIG. 10, this shows a drain cover assembly which issuitable for the protection of a drain which is bordered at the frontand on each side by a hard surface and which terminates at an opening inthe curb of a sidewalk. The assembly comprises three gaskets,respectively at the sides and the front of the polymeric sheet 1, eachgasket having an upstanding berm 23, with the outer gasket portion 22extending beyond the berm and the inner gasket portion 21 securedunderneath the polymeric sheet 1. The rear edge portion 15 of thepolymeric sheet extends upwards from the horizontal portion of thepolymeric sheet 1.

Referring now to FIG. 11, this shows a drain cover assembly which issuitable for the protection of a drain which is bordered on each side bya hard surface and which is likely to be subject to heavy flows ofwater. The assembly comprises four edge gaskets, one on each edge of thepolymeric sheet 1. Each gasket has an upstanding berm 23, an innergasket portion 21 secured underneath the polymeric sheet 1 and an outergasket portion 22 extending beyond the berm. There is an opening 7 inthe center of the self-supporting polymeric sheet. The opening 7 issurrounded by an internal gasket 6 having an upstanding berm 63 and aninternal gasket portion 62 which is secured to the self-supportingpolymeric sheet. The polymeric sheet is in the form of a peripheralborder portion 8 surrounding the opening.

1. A drain cover assembly which can be placed over a drain in the roadand which comprises (A) a self-supporting polymeric sheet whichcomprises (1) a central portion having a rectangular shape, (2) a firstside edge portion which contacts and extends from one side of thecentral portion, (3) a second edge portion which contacts and extendsfrom an opposite side of the central portion, (4) a front edge portionwhich (i) contacts and extends from a front edge of the central portionand (ii) is attached to the first and second edge portions, and (5) arear edge portion which (i) contacts and extends from a rear edge of thecentral portion and (ii) is attached to the first and second edgeportions; (B) a first side edge gasket which comprises (i) an innergasket portion which contacts and lies over or under the first side edgeportion of the polymeric sheet and (ii) an outer gasket portion whichextends away from the first side edge portion of the polymeric sheet;(C) a second side edge gasket which comprises (i) an inner gasketportion which contacts and lies over or under the second side edgeportion of the polymeric sheet and (ii) an outer gasket portion whichextends away from the second side edge portion of the polymeric sheet;(D) a front edge gasket which (i) comprises an inner gasket portionwhich contacts and lies over or under the front edge portion of thepolymeric sheet, (ii) comprises an outer gasket portion which extendsaway from the front edge portion of the polymeric sheet and (iii)contacts the first side edge gasket and the second side edge gasket; (E)a rear edge gasket which (i) comprises an inner gasket portion whichcontacts and lies over or under the rear edge portion of the polymericsheet, (ii) comprises an outer gasket portion which extends away fromthe front edge portion of the polymeric sheet and (iii) contacts thefirst side edge gasket and the second side edge gasket.
 2. A drain coverassembly according to claim 1 wherein the central portion of thepolymeric sheet comprises at least one polymeric sheet which hasapertures therein.
 3. A drain cover assembly to claim 2 wherein thecentral portion of the polymeric sheet comprises (i) a first polymericsheet which has relatively large apertures therethrough, and (ii)another polymeric sheet which has relatively large aperturestherethrough and which is the same as or different from the firstpolymeric sheet.
 4. A drain cover assembly according to claim 2 whereinthe central portion of the polymeric sheet comprises a second polymericsheet which is in contact with the first polymeric sheet and hasrelatively small apertures therethrough.
 5. A drain cover assemblyaccording to claim 4 wherein the second polymeric sheet is sandwichedbetween two polymeric sheets each having relatively large aperturestherethrough.
 6. A drain cover assembly according to claim 1 wherein thecentral portion of the polymeric sheet is in the form of a broadperipheral border surrounding an opening which (i) is not covered by thepolymeric sheet and (ii) is surrounded by an internal gasket whichincludes a berm which extends upwards away from the self-supportingpolymeric sheet.
 7. A drain cover assembly according to claim 1 whereineach of the first, second, front and rear edge gaskets comprises anupstanding berm which (i) is parallel to an edge of the central portionof the polymeric sheet, (ii) is between the inner gasket portion and theouter gasket portion of the gasket, and (iii) extends upwards away fromthe inner gasket portion and the outer gasket portion.
 8. A drain coverassembly according to claim 1 wherein each of the first, second, frontand rear edge gaskets (a) comprises a strip of a porous nonwoven fabricand (b) includes an upstanding berm which (i) is parallel to an edge ofthe central portion of the polymeric sheet, (ii) is between the innergasket portion and the outer gasket portion, (iii) extends upwards awayfrom the inner gasket portion and the outer gasket portion, and (iv) hasbeen formed by folding the strip of porous nonwoven fabric.
 9. A draincover assembly according to claim 8 wherein each of the gaskets has twoends, each of which is joined at a corner of the polymeric sheet toanother gasket so that an upstanding berm continuously surrounds thepolymeric sheet.
 10. A drain cover assembly according to claim 1 whereinthe polymeric sheet is substantially impervious to water.
 11. A draincover assembly according to claim 1 wherein the length of each of thesides of the central portion is 2-6 feet.
 12. A drain cover assemblyaccording to claim 11 wherein the length of each of the sides of thecentral portion is 2-4 feet.
 13. A drain cover assembly according toclaim 1 wherein the central portion is 4-9 inches wide and up to 7 feetlong.
 14. A drain cover assembly according to claim 1 wherein the widthof the inner gasket portion is 2-5 inches and the width of the outergasket portion is 3-10 inches.
 15. A protected drain assembly whichcomprises (1) a rectangular drain which is bordered on each side by ahard surface, and (2) a drain cover assembly according to claim 1,wherein (a) at least part of the central portion of the polymeric sheetlies over the drain and is supported by the drain, (b) at least part ofthe inner gasket portion of each of the first, second, front and rearedge gaskets is over the drain or over a part of the hard surface whichborders the drain, and (c) at least part of the outer gasket portion ofeach of the first second front and rear edge gaskets is over the hardsurface which borders the drain.
 16. A protected drain assemblyaccording to claim 11, wherein each of the first side gasket, the secondside gasket, the front edge gasket and the rear edge gasket (A) includesan upstanding berm which (i) is parallel to an edge of the centralportion of the polymeric sheet, (ii) extends upwards away from thecentral portion of the polymeric sheet, and (iii) is between the innergasket portion and the outer gasket portion, and (B) has two ends, eachof which is joined at a corner of the polymeric sheet to the end ofanother gasket so that an upstanding berm continuously surrounds thecentral portion of the polymeric sheet.
 17. A method of preparing aprotected drain assembly comprising a rectangular drain which is atleast bordered on each side by a hard surface, the method comprising (A)placing a rectangular polymeric sheet over the drain, and (B) before orafter step (A), providing gaskets which (i) are attached to edges of thepolymeric sheet and (ii) secure the edges of the polymeric sheet to thehard surface.
 18. A method according to claim 17 wherein the polymericsheet comprises a central portion which, when a liquid is placed on topof it, allows the liquid to pass through it.
 19. A method according toclaim 17 wherein the polymeric sheet is substantially impervious towater.